Compensator for firearms



Jun 1, 1948. $|EG 2,442,382

CQMPENSATOR FOR FIREARMS Filed July 9, 1945 Patented June 1, 1948 UNI-TED STAT s PATENT mm:

This invention relates to a compensator and nioreparticularly to a device "for decreasing the recoiland jumpbf a gun to which it is attached. Hertofore, conipensators for rifles have been of the type fitting over the end of the muzzle of the rifle and through which the bullet passes, the

amended April 30, 1928; 370 0. G. 757) gases discharged from the barrel striking deflecting surfaces adjacent the 'path of the bullet beyond the effective end of the barrel to counteract the recoil caused by the discharge of the bullet. These deflecting surfaces are arranged in such manner that the muzzle blast of the gun with which they are used is materially increased,

means for 'decreasingrecoil and muzzlejum'pin 'arifle.

A further object of this invention is to provide a compensator for a rifle which does not interfere with auxiliary equipment used therewith.

' 'A further object'o'f this invention is' to provide a compensator for attaching to the side of a rifle barrel which willdecrease recoil and muzzle jump of the rifle.

A further object of this invention is to provide a compensator receiving gases from the rifle bar rel before the discharge of the bullet.

A further object of this invention is to provide a compensator which will serve to reduce muzzle blast and noise.

In the drawing,

. Fig. 1 is an enlarged plan view of .the' compensator.

2 is an elevation of the compensator. v Fig. 3 is anend'view of the compensator. n Fig. 4 is a longitudinal vertical cross sectional view taken along the axis. 7 7 I l 2 Fig. 5 is a cross sectional view taken alongthe line 5-5 of Fig. 4.

Fig. 6 shows a compensator attached to a rifle barrel, the scale being smaller than that used for Figsfi'1't05. l Figflis a; perspective viewbf a cover for the by the front sight band. .i l.

compensator drawn on approximately the' sam scale as Fig. 6.

Thecompensator comprises a cylindrical'b'ody IIl of some suitable material such as steel. vThe upper side of the cylinder, that is theside adapted to be placed adjacent the rifle barrel, is provided with a flat surface H. Two ports I2 and I3 drilled in-the surface II radially to the body I0 extend to an axial bore H! in the body. The diameter of this bore is less than half the diameter of the cylindrical body III. Port I2 is normal to the bore I 4 while port I3 intersects the bore M at an angle of about degrees. Theremain' derof the body ID has a large expansion chamber I5 coaxial with the bore I4 and extending over half the length of the body. The annular wall 15 of this chamber I5 is provided with two series of slots I! and I8, one on each side thereof. Each slot comprises a vertical cut made in the side of the cylinder at an angle to the aXis thereof, the angle being such that gas discharged from the expansion chamber is directed laterally and slightly forwardly therefrom as shown in Fig; 1. The leading edges of the slots are bevcled'as' 'at I9 along a portion of the vertical length thereof to assist in directing the gas forwardly.

A nozzle 2] has a threaded end 20 which is adapted to be screwed in the bore I I which is threaded along a portion'thereof adjacent the chamber I5. The nozzle is thus axially positioned in the chamber I5 and as it is of a rela tively-small diameter there is an appreciable space between the chamber wall I6 and the nozzle. The nozzle 2| has the end 22 thereof. slight-1y tapered to increase the velocity of flow'of gases discharged therefrom. An aperture '23 in the wall of the nozzlealigns with port I3; Diametricall-y opposed notches 24in the lip of the nozzle end 22 provide means for receiving a tool to permit-inserting and removing the nozzle from the bore 'l lflv :1

The inner side of the wall I6 is threaded adjacent the free end thereof to receive the threaded portion--25 of a cap 26 designed to close the end ofthe expansion chamber. The inner side of the cap- 2515 provided with'a semispherical recess 21 spaced a short distance-from the end 22 of the nozzle and designed to receive the gases dis.- charged-therefrom to reverse their direction of A recess 3| in the lower side of the body .III: is adapted to receive the end of a setscrew carried -The mounting of; the compensatoronthe rifle barrel is il1ustrated:in 1 ig. 6. Theiundersldevof of the sight band, engages the recess 3| in the compensator to hold it in position. The compensator is .shown spaced a short distance from the muzzle of the barrel to permit a bayonet (not shown) to be attached thereto. For weapons not requiring auxiliary equipment the compensator would be placed with the end thereof flush with the muzzle of the rifle.

The operation of the device is as follows. The bullet is pushed along the barrel 28 by gases under high compression. When the bullet passes apertures 29 and 30 in the barrel the gases flow therethroug'h into the communicating ports I2 and 13 in the compensator. As the gases'fiow at right angles to the axis of the barrel the will strikethe lower side of the bore M to deliver a force'thereto which will oppose the inclination of the muzzle to jump when the bullet is discharged from the barrel 28. The gases then flow through nozzle 2! where the velocity is slightly increased upon discharge therefrom by the tapered outlet. The gases discharged from the nozzle strike the curved surface 21 of the cap 26 which reverses the direction of flow thereof. The forcegenerated by'the gases striking the cap is in a direction parallel to and opposite in sense from the recoil of the barrel clue to the discharge :of the bullet and effectively counteracts the same. The gases then pass to the expansion chamber 15 and are discharged in a lateral slightly forward direction at relatively low velocity through the groups of slots l1 and 18 on either side of the compensator to direct such gases away from the operator of the rifle. The gases discharged through the compensator produce little blast because the expansion chamber I permits reduction. of the Velocity of the gases before discharge. This expansion also rnuffies part of the noise of firing. The muzzle blast of the gun is reduced materially because of the appreciable portion of the gases discharging through the compensator. It will be seen that the gases are introduced into the compensator before the discharge of the bullet from the barrel, thus insuring a flow of gases adequate to generate an appreciable force to counteract the recoil.

The manner of use of rifles for launching grenades makes it unnecessary and undesirable to have compensat'or's operate when so used. To

render the compensator previously described inefiective, a sleeve 35, Fig. 7, is provided for closing the slots 11 and i8. This sleeve comprises a metal cylinder closed at one end and having a portion of its cylindrical side, wall cut away, as at 36 in the same plane with the flat surface H of the compensator. The inner diameter of the sleeve 35 is'of a size to permit it to slide 'over and snugly fit the end of the compensator containing the expansion chamber -5 and is of a length just sufiicient .to cover the slots l1 and I8, terminating adjacent the band 32 which holds the compensator on the barrel 28. When it is desired -to use a grenade launcher on a gun equipped with the instant invention it is merely necessary to slip the sleeve 35, over the cornpensator which will prevent the discharge of gases "from, the slots 11. and 1:8: therein.

While I have described the preferred form of my invention I do not Wish to limit myself to the precise details as shown but wish to avail myself of such variations and modifications as may come within the scope of the appended claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

13 claim? 1. The combination of a gun barrel and recoil reducing means, said means comprising a counterbored substantially cylindrical member having. a small bore portion and a large bore portion, means for securing said cylindrical member to the gun barrel adjacent the muzzle thereof with its longitudinal axis parallel to and below the longitudinal axis of the gun barrel, the gun barrel having port openings adjacent its muzzle extendin fromthe gun, bore through the bottom of the barrel, port openings in the small bore portion of said cylindrical member aligned with the gun barrel port openings, a nozzlesecured in said small bore portion and extending forwardly of the gun barrel from said port openings through the large cylindrical bore portion, the rear end of the small bore being closed, a concave cap closing the forward end of the large bore portion but spaced from the forward end of the nozzle, said cylindrical member having laterally directed slots in. opposite sides thereof, whereby projectile gases may pass from the gun barrel through the port openings to the said small bore portion and forwardly through said nozzle against said concavev cap to provide arecoil opposing force, and thence through the large bore portion to discharge through the lateral slots.

2. An anti-recoil device of the class described, comprising an elongated housing closed at its ends and having an inlet port opening laterally into-one end, its other end having a substantially concave inner surface, means forming an internal elongated tube surrounded by an annular chamber, said tube having .one. end in communication with said port and its opposite end in proximity to said other end of the housing, and the housing wall surrounding said chamber having two lateral sets of. apertures opening into said chamber in zones between the chamber ends.

JAMES E; SIEG.

' REFERENCES CITED The following references are of record in the file of thispatent: I i

UNITED STATES rA'rEN'rs Number Name 853,715 Mondragon r May 14:, 1907 933,098 McClean Sept. '7, 1909 1,003,632 McClean r Sept. 19,1911 1,738,751 Bluehdorn r Dec. 10-, :1929 2,149,512 Eiane r Mar. '7, 1939 2,191,484 Hughes g. r- Feb. 27, 1940 2,274,239 Hughes Feb. 24, 1942 2,322,370 Lance June 22, I943 FOREIGN PATENTS' Number Country Date Great Britain f l)13 

